Speculations on Armed Conflict

In a Time of Free Silicon

MARTIN LIBICKI

Chapter 2

THE SMALL AND THE MANY

Freer silicon, which portends the ability to collect enormous
quantities of data, will alter war in several stages. Pop-up
warfare describes the battlefield in which the means of war are
quiet or hidden until they rise and engage. The growing and (for
the time being) unchallenged ability of U.S. forces to lay a Mesh
over the battlefield permits the tracking and targeting of
increasingly small, quick, stealthy, and transient objects. The
logical consequence of this capability's spread is Fire-ant
warfare, a battlefield dominated by scads of sensors, emitters,
and microprojectiles.

Today, platforms rule the battlefield. In time,
however, the large, the complex, and the few will have
to yield to the small and the many. Systems composed
of millions of sensors, emitters, microbots and
miniprojectiles, will, in concert, be able to detect,
track, target, and land a weapon on any military object
large enough to carry a human. The advantage of the
small and the many will not occur overnight
everywhere; tipping points will occur at different times
in various arenas. They will be visible only in
retrospect.

The triumph of the small and the many, of
information technologies over industrial technologies,
can be discussed in terms of its three phases. The
first, pop-up warfare, is the expression of 1990's
technology under the no-longer-valid assumption that
the U.S. faces an enemy with comparable capabilities.
The second, the Mesh, describes how U.S. military
power (using technologies available over the next
twenty years) might work against a foe with developed
industrial but underdeveloped informational
capabilities. The third, fire-ant warfare, assumes
expensive sensors will themselves be vulnerable and
have to give way to networks of inexpensive
information elements.

Pop-Up
Warfare

A tilt toward quality in the quality-quantity equation
is a good sign that a military technical revolution has
occurred. During the run-up to the Gulf War, Allied
and Iraqi counts -- manpower, tanks and aircraft --
were anxiously compared. War quickly made clear
that the Iraqis could have fielded two or perhaps five
times as many men, tanks, and planes without affecting
the outcome much. Allied technology -- both
equipment and our sophistication at using it -- was so
superior (for the terrain) that exchange ratios were
overwhelmingly in its favor. We could see and they
could not. We could sneak up unnoticed and catch
them by surprise. Our weapons could be precisely
aimed while theirs were effective only against targets
several miles wide (e.g., Tel-Aviv). We were on one
side of a revolution and they were on the other.

Yet consider how differently we would have had to
operate if they had had but a fraction of our
capabilities (alternatively, what a conventional war
against the Soviets in the 1990s would have looked
like). Virtually everything we used on the battlefield
would have been vulnerable had it been visible. We
would have had to harden or hide our logistics dumps
and command and control nodes. Our tanks, were they
are to survive, would have to be hard to find except
during those few moments spent scurrying or shooting.
Surface ships would have been nearly useless anywhere
near shore. Both sides would have been driven to pop-
up warfare -- a mode in which elements are hidden and
quiet except during those brief and dangerous moments
of engagement or movement.

Among the various elements setting the stage for
pop-up warfare, the precision guided munition (PGM)
has probably been the most salient. With PGMs, any
locatable object can be precisely targeted and, most
likely, destroyed. Any object with a fixed latitude and
longitude could be targeted (with cheap, accurate
aiming systems) and struck. To do this, today's PGMs
use complex homing and terrain-matching devices
coupled with accurate gyroscopes and accelerometers.
Tomorrow's will be helped by GPS-guided seekers.
External systems would relay the latitude, longitude,
and altitude of the target, then the PGM would zip to
that point. More sophisticated systems would use real-
time updates against relatively slow-moving targets and
perhaps even local (or relative) positioning systems for
greater accuracy. Moreover, with new assets in space,
and the increasing sophistication of airborne sensors
(e.g., AWACS, JSTARS), as well as seaborne sensor
packages (e.g., Aegis Cruisers), the number of objects
that would fall under target scrutiny would increase as
well. Thus would fixed and slow-moving targets fare
poorly on a pop-up battlefield.

Pop-up warfare puts a great premium on
minimizing one's own signatures (e.g., stealth) and
amplifying the enemy's (e.g., the data fusion
capabilities of Aegis systems). Both sides would have
to stay hidden most of the time, pop up just briefly to
move or shoot, and then scurry back into the
background. To succeed, forces would quickly have
to distinguish threats from decoys and friendlies,
determine the threats' location and bearing, fire, and
then disguise and eliminate their own signature.

Can large, fixed, above-the-ground targets be
defended? Some targets can shoot back against
incoming missiles. Capital ships, for instance, are
equipped with both anti-missile missiles and close-in
weapons systems designed to disable incoming missiles
with a hail of lead. Sufficiently valuable fixed sights
might be protected by upgrades of the Patriot missile,
or follow-on versions such as Erint, THAAD, or the
Arrow. One proposal calls for hiding anti-SCUD
missiles near potential SCUD sights to chase and
overcome the latter while in boost phase.

Nevertheless, the betting has to be with the
attackers rather than their targets. Targets are bigger
than missiles, and missiles shoot first; they can succeed
in aggregate by overwhelming the defense with
numbers (many of which need only be cheap decoys).
Defense against hyperkinetic projectiles could be far
more challenging (the SCUD launches into Israel
suggest such missiles are even more dangerous after
they fall apart). A projectile that reaches Mach 10 or
20 and then releases a shower of darts clad with
ceramic (to stay intact under reentry heat) can greatly
damage soft targets. If the missile can elude
destruction prior to decomposition, mission completion
is only a matter of time.

The recent emphasis on knocking out anti-ground
missiles in their boost phase suggests the realization
that missiles will be very hard to hit once they stop
radiating heat. As it is, today's missiles -- hard enough
to hit as it is -- have yet to exploit a deep reservoir of
stealth techniques. When they have done so, they will
be far harder to hit. The logical consequence of the
missile's superior penetration capability is that their
targets would have to be dispersed, protected in very
hard bunkers, or be moved around all the time.

Pop-up warfare will evolve as signatures can be
harvested by unmanned objects: loitering missiles,
unmanned drones, unattended submersibles,
increasingly sophisticated mines. New techniques of
data fusion can help correlated such signatures.
Conversely, platforms will need more stealth to
survive. The F-117A, the B-2 and submarines are
already stealthy, but stealth is also mooted for missiles,
surface ships, and even tanks.

The contest between stealth and anti-stealth will be
long and drawn-out, but again the betting has to be
against stealth for any platform large enough to
encompass a human. A hider must suppress a bit-
stream of information that constitutes its signature. A
seeker tries to amplify these signals in order to read
them. As information technology advances, so does
the ability to amplify bits. No such mechanism favors
suppression. Indeed, an ecological axiom states that
although removing half of a pollution stream is easy,
each successive halving is harder. At very low levels,
sophisticated devices to clean up one form of pollution
often create another. Moreover, the cost of data
collection and fusion drops with the cost of silicon.
New stealth techniques, although effective, are not
getting cheaper.

Thus even with stealth, everything ultimately can be
found. All objects have mass and thus gravity. Every
object moving in a medium creates vortices and must
expend energy to do so. If nothing else, objects of a
certain size have to occupy some space for some time.
A set of sensors placed sufficiently close together can,
in theory, eventually trap everything by getting close
enough. A sufficiently fine web can intersect with any
submarine. A line of sensitive receivers placed close
enough together will find its line-of-sight path to a
beaming object cut if a bomber -- no matter how
stealthy -- rolls past. Neither architecture may be
particularly cost-effective. Yet, both show how
sensors of certain minimum discrimination placed close
enough together can, at some epsilon, catch anything.
Hence, the Mesh.

The
Mesh

Chances are good that the United States will face a
decade or probably two when it can apply military
force against opponents with greatly inferior
capabilities. Their strategy would not be to defeat
American forces in the traditional way so much as to
create as many casualties as possible in hopes that the
United States would be dissuaded from further pursuit.
Our strategy, in turn, is to use our longest suit to
control the battlefield to the greatest possible extent to
minimize exposure and casualties. As information
gathering and processing capabilities continue to
improve, our ability to see into the battlefield will
increase exponentially. This advance brings with it
both great opportunity and problems.

Combat requires doing two things: finding targets
and hitting them (while avoiding the same fate).
PGMs allow their possessors to hit most anything.
Tomorrow's meshes will allow their possessors to find
anything worth hitting. Every trend in information
technology favors the ability to collect more and more
data about a battlefield, knitting a finer and finer mesh
which can catch smaller and stealthier objects.

A long period can be expected in which elements of
the Mesh coexist with current platforms. The United
States, for instance, will probably be able to deploy
fleets of light satellites for surveillance before others
can target our existing stock of heavy low-earth
orbiters. During that interim the choice of using
platforms or the Mesh for any particular mission would
depend on which worked better or was more cost-
effective. Thus, an initial architecture for the Mesh
need not have all capabilities at once as long as
platforms to do the same job can survive.

The Mesh, at its outset, would be one part of a cue-
and-pinpoint system. Today's airborne sensor system
is a multi-layer system of satellites, large aircraft,
UAVs, manned aircraft, and finally, PGMs
themselves. Under the sea, certain types of sonobuoys
detect the presence of submarines by passive sensors,
followed by active sensors which localize the
submarine by pinging it, followed by torpedoes which
use acoustic means to land on top of it. Similarly, the
Mesh will be composed of unmanned sensors,
infiltrated into existing systems composed of large and
expensive platforms. ARPA's Warbreaker project is
experimenting with systems that proliferate sensors that
allow scanning wide areas for certain types of
signatures.

Challenges: Managing the enormous
increases in information flow is probably one of the
greatest challenges created by the workings of the
Mesh. The technical problems -- filtering, fusion, and
fanning -- are daunting enough, but the stickiest ones
deal with the distribution of information.

Consider, for instance, a joint task force formed
overnight to head off an unexpected incursion in some
otherwise forgettable corner of the world. As the
crisis starts, the relevant CINC will have a certain flow
of information from existing sensors such as satellites,
electronic listening posts, and perhaps fielded seismic
and acoustic systems. Among his first acts will be to
duplicate his enormous monitoring capabilities to some
joint task force commander. Shortly thereafter, a new
flood of information will come from various data
collection platforms such as AWACS, JSTARS, Aegis,
and perhaps small satellites and UAVs. Suddenly, the
relative trickle of information available to the
commander starts to become a current sending forth far
more data than any human can deal with. This flow
must, in turn, be apportioned to various sector
commanders for their action. Atop this flow comes a
flood of information as various platforms start to
deploy distributed air, water, and ground sensors in
various formations. These, too, then have to be
analyzed, dissected, and apportioned to the various
sub-commanders each of which has a different array of
capabilities. Managing such information blooming will
require considerable practice.

Opportunities: The development of
large effective information collection and analysis
systems permits the United States to aid an ally without
the commitment of military forces, and in some cases
without fingerprints at all. So far, the Soviet Union
has provided satellite imagery to Argentina (during the
Falklands war), and we did the same for Iraq (fighting
Iran) and the Angolan government (fighting UNITA).
The denser the overhead information, however, the
more help is available. Near real-time imagery of
Serbian artillery, for instance, might help Bosnians
more accurately target their return fire -- information
as a real force multiplier.

In times past, the United States has helped allies by
providing equipment: examples range from the Lend-
Lease program to the provision of Stingers to the
Afghan rebels. If these sensors and emitters become
global commodities (not necessarily a happy
development), the United States could still provide the
equivalent of material support. It would silently supply
the pattern recognition, data fusion, and command-and-
control software that makes these systems function.
Bytes leave no fingerprints.

Could demonstrating a Mesh, in detail, induce
surrender without the need to use much force? To do
so, requires persuading others that the ability to lock
onto a platform's precise position is tantamount to
ensuring its destruction. After all, the Gulf War allies
did not have to shoot down every Iraqi plane to win air
superiority. It sufficed to make a convincing
demonstration of "You fly -- you die." Such
correlation can be delivered through open broadcast
(e.g., via one of tomorrow's virtually infinite
channels). The potential victim is then given
opportunity to demonstrate his distance from the
targeted machine. The act of seeing oneself on
television futilely trying to hide may be very salutary.
Thus might warfare become the child's game of hide-
and-go-seek rather than the adult's game of hide-and-
go-kill.

Force Sizing: The last implication of
the Mesh is that is simplifies what would otherwise be
a difficult problem for the United States -- sizing the
forces. During the Cold War, our forces were sized
against those of the Soviet Union; without so large an
enemy, the task is far tougher. Force sizing based on
war counting (e.g., one-and-a-half wars or win-hold-
win) is likely to die a well-deserved death. The use of
capabilities-based sizing cannot satisfy for long, either.
The capabilities of others are a much better guide to
weapons development strategies (where numbers are of
limited relevance) than to weapons procurement
strategies (where numbers are highly material). To say
that military planners should disregard intentions and
focus on the strength of others logically leads to a
long-run planning goal of an armed forces capable of
defeating every one else (including our own allies) in
concert.

The rising importance of the Mesh suggests a force-
sizing calculus that could be made independent of the
precise size of the opposing threat. One precedent is
the Navy's rationale for carrier battle groups. The
argument was that the Navy needed three carrier
groups in every area to keep one on station at all
times. Before 1980, the four areas were the Atlantic,
the Mediterranean, the eastern Pacific and the western
Pacific. In 1980, adding the Indian Ocean suddenly
raised requirements from twelve to fifteen. Any debate
over the size of the threat (e.g., a putatively aggressive
Soviet Union) could be finessed; the number of oceans
rather than the size of the threat mattered. Similarly,
force planners could start by estimating the
establishment needed to deploy, operate, and service
the targets generated by a Mesh. Such a Mesh should
have minimal coverage everywhere and the ability to
go to maximal useful coverage in however many
trouble spots we have to simultaneously have to create
targeting solutions for. Done right, such calculations
should be robust against wide variations in the size and
intentions of likely threats.

Fire-Ant
Warfare

At some point in the development of the Mesh, our
forces will encounter the paradox that those platforms
whose capabilities make other platforms vulnerable are
themselves vulnerable and ultimately untenable over
the battlefield. Our surveillance planes, for instance,
not only come in highly non-stealthy platforms that do
not move too fast, but they radiate like Christmas
trees. Future engagements are likely to see even
relatively backwards nations target major sensor
platforms. Should they prove vulnerable, other ways
of restoring their surveillance capabilities will have to
be found, failing which, everyone returns to the days
of the blind.

As argued above, an equally if not more effective
way to weave a Mesh would be from millions of small
objects. They are cheap, they can get closer to the
target, and they are collectively most robust against
deliberate attack. Deploy enough of them, and they
are too cheap to kill.

An analogy to robots may better suggest the
wisdom of distributing capabilities. People perceive
robots as complex objects that, in every successive
generation, come closer to resembling man. A new
metaphor developed at MIT is that of robots as ants.
Each one exhibits certain limited aspects of
intelligence: some specialize in avoiding shadows;
others, in walking without stumbling; yet others, in
staying away from each other. Smart ants are less
powerful than smart robots, but they are small, light,
cheap, versatile, and easy to reprogram. Being cheap,
they can be built in large numbers.

Battlefield meshes, as such, can be built from
millions of sensors, emitters, and sub-nodes dedicated
to the task of collecting every interesting signature and
assessing its value and location for targeting purposes.
Many of these sensors have already appeared, albeit in
rudimentary form. In the future, they will be cheaper,
more sensitive, and capable, collectively, of receiving
signals from the various parts of the electromagnetic
spectrum. Some would be optical sensors -- perhaps
small charge-coupled devices tied to neural net
processors; they could cover not only the visible
range, but also near-ultraviolet, and all shades of
infrared. Others would act like small radar detectors,
either singly, or in computational harmony with its
like-minded neighbors. Chemical sensors could detect
the passage of machines or their men. Some would
sense changes in magnetism, air pressure, sounds,
vibration, or even gravity, and so on.

Why this proliferation of sensor types? The easy
answer is that warfighting conditions differ. Some
environments (e.g., open desert) and targets (e.g.,
surface ships) are easy to look at; other environments
and targets are tougher. To detect the latter may
require exploiting the inherent differences between
machinery and background which register on other
senses. The hard answer is that single-sensor
surveillance gives the target a single-dimension
problem to solve. Tanks strive to be hard to see and
thus employ camouflage and night movement.
Submarines strive to stay quieter, using size, baffling,
and ultra-smooth running machinery. Aircraft are
stealthy by controlling their X-band reflections by
engineering special shapes and coatings. Multi-sensor
surveillance, however, complicates the single-
dimensional problem by obviating techniques which
dampen emissions of one type at the expense of
another; moreover, the multi-dimensional problem they
create becomes that much more difficult to solve.

No one sensor need necessarily detect every
emanation from a target. The more capabilities a
sensor combines, the more expensive it gets. Thus the
fewer would be used and the easier each would be to
find and kill. Alternatively, specialized, perhaps even
single-purpose sensors, can each collect signatures,
exchange them with subnodes and
collectively form a picture of a target in its
environment.

The Mesh would also contain cheap disposable
emitters to illuminate targets with reflected radio
waves, generate confusing signatures, and broadcast
local positioning signals for precise targeting.
Although accurate positioning systems are critical for
the operation of a Mesh, full GPS capability need not
be ubiquitous (GPS can also be jammed). Emitters
that know where they sit and can broadcast relative
distances to the other elements of the Mesh may
suffice.

Some sensors may be equipped to move; they may
have little cilia-like feet on land, fins in the water, and
an airfoil (see below) in the air. Mobility would help
right errantly laid sensors, take high ground (trees,
houses, hills) in appropriate terrain, and cluster to
where other cuing systems suggest the presence of
target-rich environments. Movable sensors fitted with
precise chemicals or explosives (e.g., for taking out a
critical piece of electronics) could be the killing
mechanism in some cases.

Perhaps the prototypical sensor would be a
sandwich the size of a penny. On top would sit a
photovoltaic energy source or optical sensors; next
would be a sliver of microprocessor, perhaps a
chemical or acoustic sensor, and then a penny-sized
battery, a transmitter for an antenna jutting out to the
side, and finally some anchoring pod on the bottom.
Another design would make the sensor look like a
weed plant of a meter or two length. The shaft would
be the antenna; the head a spectral sensor device
capable of seeing as far as a human can, and the roots
would be acoustic and vibration sensors, as well as
anchors. To use yet another analogy, sensors might be
the size of bottle caps; emitters, the size of soda
straws; and miniprojectiles the size of coke
bottles.

Architectures: The transition from
single source sensors to distributed sensors has
architectural implications that will take some getting
used to. For instance, most radars today couple a
relatively cheap emitter with a relatively expensive
collector. Anti-radar missiles home in on the emitter
and by so doing and destroy the collector. Distributed
architectures would require far more computation to
translate the reflections into objects, but proliferating
emitters and spreading them far from collectors
complicates the targeting problem of the anti-radiation
missile immensely. Emitters would survive longer and
receivers would remain unscathed. When later
generations of missiles learn to recognize receivers by
their shape, the latter themselves could be distributed
among smaller networked patches. Again, the
computational requirements of putting together a big
picture increase, but the cost of computation are
continuing to decline.

Another advantage of distributing sensors both over
space and by type is that it complicates
countermeasures. An aircraft pursued by a missile
knows it is being tracked, in effect, by only one
sensor, and, more likely than not, in only one
frequency. Thus dispersed flares, even though they
travel far slower than planes, can be picked up as
aircraft by IR missiles, which can recognize the
bearing of a signal but not its distance (and thus
speed). Tracking a plane using multiple sensors
requires that the countermeasures exhibit the same
three-dimensional behavior as aircraft do; using
multiple sensors also requires all countermeasures to
stay together rather than just appear aligned by the
perspective of the missile (e.g., the flare, the jammer,
and the chaff have to travel together). This is a far
more complex undertaking.

Another feature of the Mesh is that it has the
capability to replace man-to-man coverage of a
battlefield with zone coverage. The pursuit of a given
target, which is to say, its signature, need not be
performed by chasing it. Instead the overall Mesh can
selectively pay attention to zones over which the target
is running. It tunes into successive sub-meshes by
expanding the latter's communications bandwidth and
triggering external sensors to concentrate on an area.
This shift has more than metaphorical significance; it
also alters one of the rationales of maneuver warfare.
The latter has always assumed that being there at the
right part of the battlefield was paramount. But being
there is not necessarily a prerequisite to seeing there,
and not necessarily a prerequisite to hitting there if the
range set of one's own weapons is sufficiently
dense.

The last idea suggests the eventual waning of a
currently popular theme in Army doctrine (first the
Soviet's and now ours) -- the use of overwhelming
force as a psychological disruption at the outset of an
operation. This technique may not work as well as
expected against a sufficiently well architectured Mesh.
One necessary feature in a Mesh is a sufficiently high
degree of disaggregation so that the difference between
engaging targets all at once or one at a time is
relatively minor. The second feature is at least some
practiced capability for graceful degradation so that a
percentage loss of capability does not mean a total loss
of effectiveness. The ideal is a Mesh that has no
center of gravity and thus must be defeated in
detail.

Tips of the Spear: Finding targets is
one thing, but ending their useful life takes more than
bytes. Tomorrow's weapons would likely resemble
today's PGMs. Evolutionary improvements in energy
chemicals suggest that the warheads and engines could
be somewhat smaller but probably not so small as to be
radically different creatures.

One big change would be increased use of weapons
that do not have to be borne on manned platforms;
mines are a good example. Radio contact with the
weapon and external cuing systems for its launch
would allow the weapon to be positioned closer to its
potential targets without putting platforms in harm's
way. Thus a battlefield can be seeded with air-
dropped munitions which can be raised, oriented, and
activated on command.

A second big change would be in the logic of the
seeker -- or what is left of it. Today's PGMs have to
find targets on their own. Sometimes they get external
help (reflected laser tags or radar waves); sometimes
their path is pre-programmed (e.g., cruise missiles);
sometimes they have to take advantage of passive
measures such as heat signatures or pattern
recognition. In any case, they have a nontrivial
computation to perform. Up to 90 percent of a PGM's
cost is in the guidance and control, and most of that is
in the guidance.

PGMs operating in a sensor mesh, however, can
use the latter's intelligence. A PGM that is given a
target's exactly location can get there on its own in
many ways. If GPS is jammed, it can use local
positioning signals. If it knows where it starts from,
its own gyroscopes and accelerometers will tell it
where it is going. A purely ballistic flight path may
work against slower targets. Others might simply
home in on a sensor attached to the target. A PGM
that needs less processing can use a simpler guidance
system. Thus cheaper, it can be made in greater
numbers and can defeat heavily defended targets by
saturating them with multiple incoming
warheads.

Logistics, Command and Control: The
capabilities of even the most elegant military systems
are useless without reasonable solutions to the
problems of getting them there and talking to them
when they arrive.

Getting Mesh components to where they are needed
is a problem whose solution will depend on both
circumstances and the architecture of the system
employed. A platform to insert Mesh parts is a target
no less than the platforms the Mesh was designed to
fight against. Parts which are hardened can be
dropped from air--even from space--or launched by
artillery. Sometimes, special forces could distribute
them into very small but critical areas. Micro-motors
might even, at some point, allow them to walk into
theater (but at no small demands on energy systems) or
even drift into theater. Submarines and stealthy
surface vessels may be able to lay down a naval Mesh.
All these creatures can be also delivered by civilian
means. A Mesh intended as a defensive field inside
one's borders can be deployed as a mine field might be
-- except that by separating the triggers (the sensors)
from the explosives (the PGMs), both are far harder
to detect).

Although command-and-control functions are
integral to the Mesh's operation, because a Mesh sees
no distinction between communications and operations,
the two functions are integral rather than having the
first overlaid atop the second.

The more information the sensors collect, the less
they need send to a central collection point. Radio
spectrum is limited (at the megahertz range; gigahertz
spectrum is more available but requires more energy to
tap) and battery life is precious. A high-definition
video image of a scene (which is still far less than a
human eye can see) requires 800 megahertz in raw
form, and even 20 megahertz in compressed form.
Audio input is continuous and also data-intensive.
Only anomalies could be reported.

The challenge of distributed sensors is to identify
an object by using disaggregated readings. Like neural
nets, any such meshes would have to depend on a
hierarchy of filtering and analysis. Some readings
would be matched against pre-determined patterns.
This matching requires that each sensor be able to
make partial sense of a partial reading, and that these
partial readings can be knit into a probabilistic
assessment.

The route between sensing and determination is
bound to be complicated. Some sensors -- e.g., a
particularly good eye -- might determine a target on its
own, but that would be the exception (if nothing else,
two eyes are needed to perceive depth for absolute
location). Many identifications will be probabilistic
based on, say, sightings, heat signatures, sounds, and
perhaps chemical emanations. This faculty will be
critical when the other employs decoys -- not
everything that appears to be a tank actually is one.
Because battlefields will always feature new and
different objects, sensor processors will have to be
capable of some level of logic abstraction. Humans,
as multi-sensor creatures, are for that reason very good
at identifying objects. However, there is no inherent
reason to pack two eyes, two ears, and a nose on every
sensor if these functions can be distributed amongst
many of them. (Perhaps one needs a hundred eyes as
often as one needs ten ears or one nose.)

To coordinate, sensors each would have to talk to
one another; their activities would have to respond to
what others sense (comparable to moving eyes to
follow something). Some of these sensors would have
to act primarily as nodal processors, collecting
information from other sensors to assess a pattern.
These too would have to be proliferated to assured
robustness; even higher level nodal functions would, in
turn, be scattered throughout the battlefield in lesser
densities, and so on down to those communicating
directly to humans, off-site coordinators, and/or fire
control units.

A key coordination problem among sensors is how
to identify themselves upon disbursement. Each must
indicate where it has landed, how well it is
functioning, and who it is near (and thus will be
talking to). Many sensors will die on arrival; others
may be incapacitated by virtue of their poor placement.
Inevitable gaps in coverage will require that sensors be
added, moved around, or converted from one type to
another (e.g., we have enough sensors listening to this,
listen to that instead). Constant communications would
then be needed to determine which sensors still work,
which are silent, and which are phony (digital
signature can prevent spoofing but requires that sensors
know who their neighbors are). Such communications
also would indicate where more coverage is
needed.

Vulnerabilities: The most prominent
vulnerability of a distributed Mesh is that the links
among sensors, emitters, and microprojectiles are key
to its operation. Unlike complex platforms which
couple their various capabilities internally, capabilities
of the Mesh are coupled externally; thus they may be
disrupted by what the Soviets called "radio-electronic
warfare."

Sensor broadcasts can, in theory, be jammed or
faked, just as those from platforms can. Yet, doing so
may be harder than it looks. Jamming requires
knowing exactly which frequencies are being used, but
more important, where signals are coming from.
Today's jammers tend to disrupt a signal from one
point to another operating in support of a mission
(e.g., confound reflections from a large radar meant to
be bounced off an incoming bomber). With
proliferated sensors, the only effective jamming
technique would be to overpower radio signals by
jamming continuously in all directions. This technique
requires considerable energy--a fact that makes a
jammer a highly visible target itself. Besides taking
advantage of existing techniques to avoid jamming --
frequency hopping, spread spectrum, extreme
directionality -- the Mesh might also use laser
communications, acoustic means, hopping on enemy
frequencies, or just not communicating for long
periods of time. Indeed, frequent among Mesh
communications might be the repeated admonishment
to stay quiet for a while because the enemy is trying to
smoke you out. Thus, no one could be really sure that
all emitting elements in would be silenced (or just
waiting for the right time to turn on).

Faking the broadcast of a digital emitter is even
more difficult. By broadcasting a digital signature, a
sensor can simultaneously ascertain that the message is
actually coming from the sensor, and that the message
received was actually that which was broadcast.
(Corrupted messages would be internally inconsistent.)
This technique requires that each broadcasting sensor
have a unique signature and that each receiving sensor
memorize the signature of each broadcasting sensor --
this is a memory burden, but one which becomes
easier with every passing year. Moreover, techniques
that allow a communicator to sign a message also
permit them to send out false messages knowing that
they will be ignored but hoping the enemy will, if not
listen, then at least waste power jamming on a
frequency not being used.

Platforms Against Fire-
Ants

The fate of platforms can be illustrated by
examining how they might fare against fire-ant
elements.

Tanks: Consider the tank as it rolls
over terrain littered with sensors and emitters backed
by hidden microprojectiles. Such sensors may have
arrived hours earlier or they may lie buried for years
awaiting a wake-up call. Sensors to search for large
ground objects need not be located on the ground.
Much of the load may be carried by drones that can
broadcast more information than today's models, stay
aloft longer, operate more stealthily, and cost less. If
costs get enough attention, the deployment of many
good drones will be preferred to a few great
ones.

An unfriendly tank passing by sensor fields could
be brought down in several ways. The most direct
solution, if available, is to broadcast the tank's location
in real-time to an external missile (or some other fire-
control solution). Sensors may also be rigged to take
a more direct role. A sensor, for instance, that rides
atop a passing tank (much as fleas on passing dogs)
can serve as a homing device for an anti-tank round.
Of course, it must work quickly before it is detected
by the tank's smart skin and removed. Sensors may
amble over to a tank's vulnerable parts, then kill it by
eating its way through gaskets, fuzing moveable parts
(e.g., a powdered aluminum-magnesium burst),
befouling its air supply, jamming its electronics,
smearing its optics, and so on. The latter methods
may well evolve from current research on non-lethal
warfare. To wit, the chemicals required to stop a tank
without killing its crew may be far more compact and
thus efficient than those required to blow it up.

Planes: Today's aircraft are optimized -
- at great expense -- to win one-on-one (or one-on-not-
too-many) duels against other aircraft and anti-aircraft
ground units. The fate of fifty million dollars' worth
of aircraft (roughly one) contesting fifty million
dollars' worth of loitering sensors, emitters, micro-
projectiles may be far less satisfying.

An air-borne sensor screen might contain thousands
of nasty objects that may collectively cue firing units
in real-time by announcing a target's location and
bearing, illuminating it with spattered chemicals, or by
bouncing radar on it. Alternatively, if such objects
exploded a rain of carbon fibers or ceramic shards,
they could take down the aircraft's engines on their
own.

Although current technologies do not allow objects
to loiter in the air very cheaply (helium balloons
aside), today's drones can stay aloft for two weeks. A
typical floater may, in a few decades, be the size and
shape of a handkerchief, powered by a coat of
photovoltaic paint, and girded by a semi-rigid skeleton
acting as both antenna and air-sail. Its sensors and
processors, no larger than fingernails, would allow it
to sense wind movements and configure itself to bob
up and down accordingly. Upon detecting hostile
aircraft, it so signals to fire-control units or tries to get
itself and thousands of its friends to find their way
softly into the aircrafts' engines. To friendly aircraft,
it sends what it knows about the not-so-friendly skies
and otherwise gets out of its way. These floaters need
not be stealthy; when deployed in the millions, they
will simply be beyond the capability of anything to
shoot down.

Ships: The same problem of coping
with scads of hostile objects would also bedevil ships
and submarines. The elements of a Naval mesh are
presaged by sonobuoys -- cheap sensors routinely
produced in the hundreds of thousands today. Lower
power requirements, more efficient batteries, and
perhaps tethered photo-voltaic collectors will give
future versions longer lives. They will also be able to
sense better, process more information themselves, and
communicate both with their peers (vice overhead
aircraft) and associated floating torpedoes. They may
even be armed and could maneuver to where ships are
most vulnerable. Anti-submarine aircraft squadrons
will be used only for initial distribution. If sonobuoys
can loiter for years until activated, a much smaller
fleet of them could handled even this task.

Naval meshes might be supported by fleets of
robotic submersibles -- perhaps just very large
torpedoes -- that can chase fast or stealthy targets into
heavily mined waters. To protect themselves, ships
and submarines would have to physically sweep large
stretches of sea before them. They may need a layered
net swept fore and aft to a distance of several miles.
This would slow them down considerably and reduce
their efficacy in a power projection role.

Space: Tomorrow's space forces will
combine very high earth orbiters with large fleets of
very low earth orbiters. Their tasks will, however, be
the same ones they carry out today: communications,
observation, navigation.

One shift will be from strategic to tactical uses of
surveillance (already being developed in the TENCAP
program). To support targeting and treaty compliance,
strategic surveillance needs very detailed pictures (e.g.,
10 cm resolution) of compact spaces looking for
installations that rarely move. Tactical surveillance,
although it can use the detail, needs more real-time
information. Coverage also needs to be wider because,
in a typical tactical scenario (e.g., Bosnia) the field of
action is not fixed; it can move quickly and
unpredictably. Today's needs for wide-area coverage -
- looking for certain high-energy events like the launch
of a SCUD missile, for example -- are met by large
satellites in geosynchronous orbit. At forty thousand
kilometers up, such orbiters are usually too distant to
localize such events precisely. Tactical operations
need much denser coverage, and probably from much
closer.

Large earth orbiters are also vulnerable to anti-
satellite systems no better than those the United States
demonstrated off the wings of an F-15 in the middle
1980s. Eventually, large earth orbiters will prove
nearly impossible to hide because they are hard to
camouflage against an earth background. Since every
one must cross the equator fifteen times a day, constant
searching can be confined to a small equatorial band.
From a higher equatorial orbit, precise optics coupled
with powerful on-board processing would make a first
sighting inevitable. The movement of satellites, once
spotted, can be predicted with great accuracy.
Satellites that use energy to jerk into unpredictable
orbits would emit characteristic energy plumes that
would instantly cue seekers to the orbital path. Under
such circumstances, a spacecraft would be hard put to
get more than one or two passes over the battlefield
before being targeted and destroyed.

Hence the watchwords will be to fly high (and thus
get lost in far vaster reaches) or fly small and dense.
The logic of space dominance would require getting
the most capability into orbit the fastest and protecting
it there against attack the longest. This capability
would provide short-term tactical advantages at
precisely the right moment. Satellites made small and
cheap enough could proliferate and thus make their
complete destruction complicated. Surveillance
satellites might therefore survive better in the
aggregate. Weapons satellites (if not forbidden by
current treaties) might not -- due to the added size and
weight of a platforms required to carry a minimally
effective warhead.

Continuous real-time coverage from space would
remain unfeasible until satellites become far cheaper.
The best look comes from orbiting 400km high (below
which atmospheric drag pulls satellites back to earth,
and above which complicates the optics problem).
From there, a 30- degree field of view to each side
yields a 400km swatch but requires 4000 birds (90
birds per each of 45 orbits) to maintain continuous
coverage (between the north and south 60-degree
parallels). Affording this fleet within a feasible $20
billion investment budget would require that each bird
and shot be less than $5 million. Split 50:50
(assuming $6000 per pound. to low-earth orbit)
suggests that each satellite cost less than $2,500,000
and weigh less than 400kg.

The data burden from such a system is big. To
picture everything in the world in one meter resolution
with 8-bit detail requires roughly 1,500 terabits. If
each point is shot once a minute, a total send rate of
3,000 gigabits/second is required. Even with 10:1
image compression and 4000 satellites, each bird must
broadcast 600 megabits per second (roughly equivalent
to thirty TV signals). Further reduction is possible by
sending only the difference between the actual and
expected image, although this requires each bird to
store 18,000 gigabytes (150 terabits) of image per bird
-- free silicon in the extreme. If the resolution doubles,
the data collected must rise fourfold. Staring satellites
can cover known swathes more efficiently, but
successful use of the technique assumes the area
covered is significantly smaller than Bosnia. Longer
revisit times return us to the current system, which is
unusable for real-time operations.

Looking up rather than down, denser information
technology makes it easier to construct a functioning
ballistic missile defense. A dense enough sensor
system should be able to track missiles, which must be
large (if they are to hold nuclear weapons) and fly
against a fairly clear background. Destroying the
missile once it is found, is considered the lesser half of
the problem.

Broader
Implications

By changing the conduct of war, the Mesh changes
its nature as well. It raises serious questions about
human command, affects the pace of conflict, and
blurs the distinction between civilian and military on
the battlefield.

Human Control: Current leitmotifs of
information warfare suggest that because militaries
possess a command core linked to field armies by
command and control networks, killing the core leads
to cheap victory. Yet advances in information
technologies may mean that the core need not sit in
any one location. Teleconferencing, for example,
permits a command center to occupy dispersed
locations. The core data base can be duplicated in
many locations (or can be built as an distributed system
to begin with).

Human command would also evolve. Information
technology permits greater centralization -- because
better telecommunications increase the amount of data
that can be sent to core. However, it also permits
greater decentralization -- because better computation
allows units to handle more data from colleagues.
Tomorrow's military systems will do both.
Headquarters will be able to do more detailed unit
control, but units will be able to undertake more
functions in degraded communications
environments.

Meshes could be engineered to take humans out of
many decision loops. Complete removal from the loop
is possible. Yet, a technology which
permits less human oversight need not
compel it. The bogeyman of an automated
war machine will be no greater than it is today. As it
is, many existing weapons lack call-back mechanisms.
Most mines, for instance, have no man-in-the-loop
between detection and explosion. Once a ship's close-
in weapons system is turned on, its choice of targets is
determined automatically. How different are a
strategic ballistic missile that leaves human control
once launched and a loitering cruise missile that
searches for and destroys a target on its own?

Could fire-ant systems elude human control
altogether? Hollywood likes making movies such as
Fail-Safe, Dr. Strangelove, War Games,
and Terminator 2 that show strategic
systems going autonomous. Accidental system
autonomy in conventional systems is a lesser problem
because they contain multiple decision points and do
not have to make all decisions at once. Regardless of
how complex the software, the inclusion of enough if-
maybe-then-stop locks can limit the risks. An
adversary may, however, establish a doomsday ant-
mesh system -- but these concerns are not new; they
have been familiar grist to nuclear theologists for
decades.

In a battlefield in which machines command others,
foot soldiers -- whose relative ranks have been
dwindling for a few hundred years -- may be the only
humans left. Platforms already dominate low-density
environments such as air, sea, plains, and deserts with
their ample running room; these platforms, in turn will
be supplanted by the Mesh. High-density
environments such as cities, jungles, and mountains
remain the preserve of the foot soldier; the Mesh will
take over much more slowly in such realms. Foot
soldiers can still benefit from technology. Helmets, for
instance, may house cellular radio receivers, IFFN
transponders, video display terminals embedded in
pull-down visors, and computers. The latter would
coordinate sensor inputs, generate tactical assessments
of battlefield conditions, and transmit maps.
Passwords or biological makers could ensure that only
the owner be able to use them. The individual soldier
could thus be made part of the military Mesh (as well
as the commercial Net).

The Pace of Conflict: The Mesh may
be tomorrow's version of what the Maginot line was
supposed to be, a barrier through which no platform
can transit without being detected and destroyed. The
Maginot line -- despite its subsequent reputation --
succeeded where it was placed. Unfortunately,
because it cost so much to build, France was unable to
finish it, and Germany ran around it to the south.
Mesh warfare favors defense. However, unlike the
technology of World War I, which also favored the
defense, in the next century each side will be able to
bombard the other's civilian infrastructure with relative
ease. Thus, it will be possible to destroy an
opponent's above-the-ground civilization without being
able to occupy its territory.

Conflict may then resemble siege warfare--perhaps
even mutual siege warfare. The same cordon
sanitaire technology that can protect a state
against invasion can be used by invaders to blockade
defenders. Offensive siege operations are a highly
unsatisfactory way of going about war for all the usual
reasons: they are slow, uncertain, and hurt the
powerless while the powerful can claim scarce
resources for their own ends. Iraq's experience after
the Gulf War is a good example. Long-term
maintenance is also a problem. In the 21st century,
how long might technology allow a besieged party to
endure a total blockade? Would modern polities have
the patience or stomach to maintain sieges over years,
as the besieged project pitiful images of their victims?
Would technology let the besieger blockade such
electronic communications or douse the besieged with
messages of panic or despair? If such sieges prove
impossible -- societies always prove surprisingly
resilient against aerial attack -- what other techniques
would be available to contain aggressors one could not
destroy?

Mesh warfare could simultaneously be faster and
slower than current conventional warfare. Compared
to the several months the United States needed to
deploy to the Gulf, a mesh could be laid down in
several hours. A heavy lifter could transit over the
affected area, dispersing large quantities of sensors,
emitters, microbots, and miniprojectiles. Upon
landing, they would automatically configure themselves
into a coordinated network. Some countries may leave
heavy lifters on runways for precisely such
contingencies. Perhaps the United States could protect
a future Kuwait upon first hearing that it had been
invaded, although such a policy would not be an
unalloyed plus. The ability to promise quick
commitments may deprive decisionmakers of the time
needed to contemplate the long-run consequences of
such decisions. National leaders could regret not
leaving erstwhile allies to their own devices.

If both sides tried to set up meshes at the same
time, would the race be destabilizing? Provided both
mined inside their borders, setting up a fence might, at
worst, compel an opponent to set up its. Often,
however, such distinctions are not so pat. One party's
fence may include disputed or third-party territory.
Many collectors see over boundaries: airborne sensors
can enjoy a 300km line of sight; sensitive seismic or
acoustic sensors can monitor the entire world.
Establishing the space component of the Mesh may
also induce conflict particularly if the first up can
prevent the second from getting up. World War I was
supposedly accelerated by the competition among
various countries to mobilize their troops at the border
before the other side could. Once the trains, with their
rigid timetables, started moving, momentum moved
with them to war.

While a Mesh may be built quickly, its operation
may retard war considerably. A recent RAND study
argued that a squadron of B-2 bombers could destroy
an invading armored column in the open. Knowing
this, what country would be foolish enough to afford
us such opportunity? Instead, unless an invasion could
be completed in a few hours, a conventional invasion
force opposing a high-information opponent would
want to do so very gingerly, with methods similar to
those submarine warfare. The Achilles heel in any
information system is the extent to which it can be
spoofed -- a constant throughout military history. An
effective strategy would have to combine false
negatives (sneaking through untouched) and false
positives (decoys). Some methods work better than
others. To find a tank requires looking for a
correlation among as many parameters as possible.
Yet finders must be flexible to see that if something
looks like a tank, walks like a tank, quacks like a tank,
but does not smell like a tank, it may nevertheless be
a tank. Conversely, a decoy does not have to simulate
a tank in every respect to be classified as one -- just in
all features considered important by the other side. It
may require many decoys to find which parameters the
opposing software deems important and thus uses for
target identification. All this assumes, of course, that
in an attrition conflict one can trade decoys for missiles
and still emerge on top. Conversely, a Mesh may let
a few tanks by to hide its true parameters. For these
reasons, the offense will want to move very slowly
while searching for weak spots in the system.

Another technique may take advantage of the fact
that the ability to transmit information among many of
the nodes may be limited by the small amount of
spectrum they each have. Thus a strategy of flooding
certain nodes with information may degrade the
system. In a poorly engineered system, relevant
signature information will be randomly dropped. Even
in the best engineered system, concentrating on the
important data will force the less highly ranked but still
threat-defining data flows to be dropped. Either way,
the defense deteriorates. However, determining the
information architecture of the other side's Mesh to
know exactly where it is weak is anything but
easy.

It is not clear how one side's Mesh would combat
another side's Mesh. Most sensors and miniprojectiles
would not only be small, and at least partially buried,
but quiet as well; they would be listening much and
transmitting rarely. Might hunter-killer microbots be
developed to search out and destroy their opposing
numbers? Both the difficulty of the likely terrain and
their slow speed suggest that such an effort would be
extremely drawn out. Confirming that an area is safe
is even harder, particularly if the Mesh lets a few
items through as a trick.

Economics may also inhibit an ant-on-ant warfare
strategy. By virtue of their mobility and additional
sensors, hunter-killer ants are bound to be more
expensive than their more passive victims. If the
hunter-killers have to get close to passive sensors to
find them, then a certain percentage of the victims
could be mined to blow up upon being jostled by a
hunter-killer. At some percentage those employing
hunter-killers must expend more resources than they
disable. Killing from afar could easily require
armament that is more expensive than the individual
sensors themselves, and so on.

Civilian as Military: Mesh warfare not
only makes it hard to keep platforms alive on the
battlefield, but complicates the task of getting them
anywhere near it. Logistics assets, notably airlift,
sealift, and prepositioned supplies, are among the
largest and slowest of military assets. The difficulty of
getting there against an opposing Mesh should be of
particular concern for the United States and others who
help allies by projecting power over large
distances.

Because, paradoxically, lift assets are among the
most civilianized of military assets, the solution to the
lift problem may be to consciously imitate civilian
assets until very close to theater. A ship used to carry
war material for West Island would be
indistinguishable from one used to carry commerce to
East Island. At some point its destination would be
obvious, but by then, it might have already passed its
load of sensors and emitters to where needed. East
Island could counter this strategy by explicitly granting
a digital signature to specific ships, planes, and
messages it selects for its own trade. It is not clear
whether other nations would cooperate in setting up an
IFFN tracking system with a nation that attacks world
commerce. Otherwise, East Island would have
difficulty isolating West Island from military help
without isolating itself from the commercial world it
was increasingly networked to.

Wars are not just contests. Removing all platforms
-- and thus those who man them -- from the field of
war would not make war safe for everyone, but the
opposite. If Meshes promote siege warfare or the
civilianizing of military assets, then the distinction
between military and civilian erodes to the great
detriment of the latter -- a reminder, again, that not
every advance in the art of war is tantamount to an
advance in civilization.

Conclusions

Regardless of how the many implications of pop-up
warfare, fire-ant warfare or the Mesh play out, one
conclusion is inescapable. The days of the platform as
the king of the battlefield are drawing nigh. With its
eventual demise comes a similar demise of
organizations built around such platforms and the
systems used in acquiring them. To these, the essay
now turns.